D-Link DPH-120SE User Manual page 77

access to enterprise inner network from public network. That is to say, you can set
it to connect public networks in different areas into inner network via a special
tunnel.
Field name
VPN IP
Select L2TP. You can choose only one for current state. After you select it,
you'd better save configuration and reboot your phone.
Enable VPN
VPN Server
Address
VPN User
VPN Password
VPN Configuration
explanation
Shows the current VPN IP address.
Select it or not to enable or disable VPN.
Set VPN L2TP Server IP address.
Set User Name access to VPN L2TP Server.
Set Password access to VPN L2TP Server.